Percutaneous transforaminal endoscopic discectomy and miniincision surgery in the treatment of lumbar intervertebral disc protrusion.

Lumbar intervertebral disc protrusion (LIDP) is a frequently occurring disease and 10-20% of patients require surgical treatment. Percutaneous transforaminal endoscopic discectomy (PTED) and mini-incision surgery are currently the most common surgeries for patients. To analyze the efficacy of PTED and mini-incision surgery in the treatment of lumbar intervertebral disc protrusion, this study selected 216 patients with LIDP who were admitted to the hospital between February 2014 and June 2015. The subjects were randomly divided into an observation group and a control group, 108 each. Patients in the observation groups were treated by PTED, while patients in the control group were treated by mini-incision surgery, and treatment efficacy of the two groups was observed. The results demonstrated that the duration of surgery and length of hospital stay of the observation group were significantly shorter than those of the control group, the intraoperative blood loss of the observation group was significantly less than that of the control group and the size of surgical incision of the observation group was much smaller than that of the control group (P less than 0.05). As to clinical efficacy, in accordance with the Japanese Orthopaedic Association (JOA) score and the Visual Analogue Scale (VAS) score, results of the observation group were superior to those of the control group at 3 months after surgery (P less than 0.05). In conclusion, treating patients with LIDP through PTED can significantly improve treatment efficacy, shorten surgical and healing time and relieve pain. This therapy is worth clinical promotion.

MicroRNA-207 enhances radiation-induced apoptosis by directly targeting Akt3 in cochlea hair cells.

MicroRNAs (miRNAs) have important roles in various types of cellular biological processes. Our study aimed to determine whether miRNAs function in the regulation of ionizing radiation (IR)-induced cell death in auditory cells and to determine how they affect the cellular response to IR. Microarray and qRT-PCR were performed to identify and confirm the differential expression of miRNAs in the cochlea hair cell line HEI-OC1 and in vivo after IR. Upregulation or downregulation of miRNAs using miRNA mimics or inhibitor were detected to characterize the biological effects of the indicated miRNAs. Bioinformatic analyses, luciferase reporter assays and mRNA knockdown were performed to identify a miRNA target gene. We determined that miR-207 was significantly upregulated after IR. MiR-207 enhances IR-induced apoptosis and DNA damage in HEI-OC1 cells. Furthermore, Akt3 was confirmed to be a direct target of miR-207. Downregulation of Akt3 mimics the effects of miR-207. MiR-207 enhances IR-induced apoptosis by directly targeting Akt3 and anti-miR-207 may have a potential role in protecting cochlea hair cells from IR.

Cardiorespiratory fitness and isokinetic muscle strength of elite Asian junior soccer players.

There is a scarcity of descriptive data on the physiological characteristics of elite Asian junior soccer players. The purpose of this study was to evaluate the cardiorespiratory fitness and isokinetic muscle strength of elite junior soccer players in Hong Kong. It was conducted in conjunction with the selection of the Hong Kong team to the 1989 Gothia Cup held in Sweden. Twenty-one top junior soccer players were selected as subjects for the study. The following means (+/- SD) were observed: age 17.3 +/- 1.1 years; height 172.5 +/- 6.2 cm; weight 62.8 +/- 7.0 kg; body fat 5.2 +/- 1.8%; forced vital capacity (FVC) 4.6 +/- 0.6 L; maximum oxygen uptake (VO2max) 58.6 +/- 2.9 ml.kg-1.min-1; anaerobic threshold (AT) 76.7 +/- 10.2% of VO2max; peak isokinetic dominant knee extensor and flexor strengths 3.28 +/- 0.37 Nm.kg-1 and 1.84 +/- 0.24 Nm.kg-1; hamstring to quadriceps peak torque ratio (H/Q) 56 +/- 0.6% measured at 60 degrees s-1. Hong Kong players appeared to have comparable aerobic power, light body weight, poor flexibility and above average isokinetic muscle strength compared to other international junior soccer players. Training programs to improve the contralateral knee muscle imbalance and to increase the fast speed movement capability of the non-dominant knee flexors are recommended.

Echoicity of whole blood.

A clear relationship was found to exist when the echoicity of whole blood under different flow conditions was determined and related to its corresponding ultrasonic backscattering properties. The results indicate that the echoicity of whole blood is shear rate and species dependent. Echoicity of porcine whole blood was found to decrease as the shear rate was increased, whereas the echoicity of bovine whole blood was found to be shear rate independent. At the same shear rate and hematocrit, the echoicity of human and porcine whole blood was found to be higher than that of bovine whole blood. These observations can be readily understood when red cell aggregation is considered. In imaging porcine whole blood under steady laminar flow, under certain conditions a hypoechoic region was observed to appear near the center of the flow conduit. The behavior of this hypoechoic region and the mechanisms responsible for its appearance are not entirely clear at present.

Ultrasonic backscatter from flowing whole blood. II: Dependence on frequency and fibrinogen concentration.

Earlier studies showed that ultrasonic backscatter from erythrocytes suspended in saline is a function of hematocrit and frequency and that it can be affected by flow disturbance. The experimental data agree well with the theories. Recently, studies have been extended to flowing whole blood. The results indicated that ultrasonic backscatter from flowing whole blood differs from that from saline suspensions of erythrocytes in that it is shear-rate dependent and species dependent. In the present article, data on the dependence of ultrasonic backscatter from flowing whole blood on frequency and on fibrinogen concentration are reported. It was found that ultrasonic backscatter from flowing whole blood also depends on fibrinogen concentration when red blood cell (RBC) aggregation exists. Moreover, when the blood is under conditions that favor RBC aggregation such as low shear rates, high fibrinogen concentration, or high hematocrits, Rayleigh scattering apparently is no longer sufficient to describe its scattering behavior.

Ultrasonic backscatter from flowing whole blood. I: Dependence on shear rate and hematocrit.

Previous results show that ultrasonic backscatter from red blood cells (RBCs) suspended in saline is a function of hematocrit and frequency and that it can be affected by flow disturbance. The experimental data agree well with the theories. In the present article, results on ultrasonic backscatter from flowing whole blood are reported. Studies have been conducted on porcine, bovine, and human blood. Ultrasonic backscatter of flowing whole blood differs from that of RBC suspensions in that it is shear-rate dependent, which means that it is a function of spatial position of the blood in the flow conduit. Moreover, the results indicate that it is also species dependent. This behavior can be readily understood when red cell aggregation is considered.

The effect of focusing on ultrasonic backscatter measurements.

In this paper, the effect of transducer focusing on the integrity of ultrasonic backscattering measurements is examined. The rationale for this study stems from our observation that the calculated values of backscattering coefficients from data obtained with nonfocused transducers are always substantially lower than those obtained with focused transducers when the standard substitution method is used for backscattering measurements. It is postulated that this discrepancy is caused by the extremely complicated beam behavior of a focused transducer. This hypothesis is verified experimentally. It is therefore concluded that focused transducer could yield misleading results when a standard substitution method is used for absolute backscattering measurements.

Effect of flow disturbance on ultrasonic backscatter from blood.

Due to the better resolution and performance provided by the new generation of real-time high resolution ultrasonic scanners, blood now becomes a tissue which can also be visualized ultrasonically. There is strong experimental evidence indicating that the echogenicity of blood is increased as a result of erythrocyte aggregation. In this paper, we will show that flow disturbance may also play a significant role in influencing blood ultrasonic backscatter or echogenicity. Our results indicate that the introduction of turbulent flow can cause ultrasonic backscatter from erythrocyte suspensions to increase appreciably for hematocrits greater than 10%. We will also show that this increase may be correlated to the turbulent intensity. Moreover, the scattering peak is observed to shift to lower hematocrits when turbulence is eliminated. Experimental results obtained for uniform flow are in excellent agreement with theoretical models for small spherical scatterers which predict a scattering maximum at a hematocrit of 13%.

Ultrasonic characterization of blood during coagulation.

Recently ultrasound has been found to be extremely useful in detecting intracardiac thrombi as well as intracranial hemorrhages in neonates. The principal criterion used for clinical diagnosis of thrombus has been an increase in the echogenicity of clotted blood. However, echogenicity is a rather nonspecific and qualitative description of tissue ultrasonic properties. A rise in echogenicity could be the result of an increase in ultrasonic backscatter, or a decrease in attenuation, or a combination of both. In order to ascertain the mechanism responsible for the clinically observed increase in echogenicity and thus put the technique on a firm foundation, we have measured serially the ultrasonic velocity, attenuation and backscatter in human blood up to 24 hours following the onset of coagulation. Preliminary results show that all three ultrasonic properties increase during this time period. At 24 hours following clotting, the mean rises in velocity, attenuation and backscatter are 3.36 +/- 0.35 X 10(3) cm/sec, 2.3 +/- 0.22 db/cm and 18.5 +/- 1.2 dB per unit volume of blood (at 7.5 MHz and a temperature of 23 degrees C), respectively. These results indicate that the increase in echogenicity of a thrombus is due to a substantial increase in ultrasonic backscatter, which is moderated to a certain extent by the accompanied increase in attenuation.